Korean profiler analyzes why suspect in ”random high school girl murder” laughed after the crime

Regarding the grin on the face of suspect Park Dae-seong, who murdered a high school girl he did not know in Suncheon, South Jeolla Province, after the crime, experts have commented, "He must have been satisfied."
He also pointed out the possibility that if he had not been caught by the police, he could have been involved in another murder.
"When you carry out a murderous act in a state where you have a heightened desire to kill someone, the satisfaction of the act leads to an unconscious state of laughter or excitement that continues on and on. This is called 'post-murder arousal.' If this state continues,
"Serial killers laugh and get excited all the time, which makes them unconsciously smile and turn up the corners of their mouths. They also run around.
"The case of Cho Song, who brandished a weapon near Sindorim Station in July 2023, is similar to that of Choi Won, who brandished a weapon near Seohyun Station.
"The same symptoms were seen in prisoner John," he explained. Prior to this, Professor Lee Suzy-yeon of the Department of Criminal Psychology at Kyunggi University also said on CBS Radio on the 2nd, "When you achieve your goal, you feel a sense of satisfaction.
Regarding Park's statement that he "drank and lost his memory," Bae said, "(Park) was drinking and lost his memory.
"It appears that he was not mentally infirm, but rather warmed up his body to commit the crime," he said. "Given that he has several criminal records for violence, he may have been training for serial murders. Park does not appear to be weak.
Park was arrested on suspicion of stabbing and killing a 17-year-old high school girl with a deadly weapon on the side of the road in Cheorye-dong, Suncheon City at around 12:43 a.m. on the 26th of last month.
Park drank four bottles of soju at a restaurant he owned, left the kitchen with the murder weapon, and then followed the high school girl for about 800 meters before committing the crime.
He drank at karaoke bars and in other establishments for an hour and a half to two hours, and when he started to make a false accusation against a man, he was subdued and arrested by police who were dispatched to the scene.
Park was captured on CCTV walking barefoot and laughing immediately after the crime.
During the substantive review of the warrant, he said "I'm sorry," but his mouth corners appeared to turn up, further angering the judge.